It was known that lichens produce unique secondary metabolites different from those of higher plants (Ingolfsdottir, K., Phytochemistry, 61:729, 2002), most of the secondary metabolites produced by lichens belong to depside, depsidone, and dibenzfurane, and these compounds are estimated to be associated with a low growth rate of lichens (Kumar, K. C. S. et al., J. Nat. Prod., 62:817, 1999; Huneck, S., Naturwissenschaften, 86:559, 1999). In addition, various biological activities including antibiotic, antimicrobactrial, antiviral, analgesic, and antipyretic activities, and the like, were confirmed by a screening process of the metabolites of lichens (Ingolfsdottir, K., Phytochemistry, 61:729, 2002; Kumar, K. C. S. et al., J. Nat. Prod., 62:817, 1999). Therefore, the interest in the development of a medicine using the secondary metabolites of lichens has increased.
Meanwhile, the liver is a tissue playing a pivotal role in metabolism of materials from outside the body and materials inside the body. Alcoholic or viral hepatitis develops cirrhosis or liver cancer, but currently, there is no distinct therapeutic material for cirrhosis. Since there are no pains or subjective symptoms in an early stage of hepatic fibrosis, and hepatic fibrosis is found in an end stage, mortality is high, thereby causing social problems. In Northeast Asia and Southeast Asia including China, an expression rate of diseases associated with viral (alcoholic) liver cirrhosis and liver cancer is seriously high. In the case of a therapeutic agent for viral hepatitis, new medicine development has been actively conducted and has been successful in the market, but there is no therapeutic agent for liver cirrhosis except for ursodeoxycholic acid and silymarin. Therefore, in the case of securing a novel material capable of preventing and treating liver cirrhosis, the novel material will be a significant influence on a market in the future.
Therefore, the present inventors have tried to provide a novel material capable of preventing and treating liver cirrhosis and found that ramalin has an effect of preventing and treating hepatic fibrosis and liver cirrhosis in a liver cirrhosis animal model, thereby completing the present invention.
This information disclosed in the present technical field is only to improve understanding of a background of the present invention. Therefore, information on the prior art that is already known by those skilled in the art to which the present invention pertains may not be included.